The organization of brain aminergic systems will be investigated by measurements of catecholamine parameter after lesions of aminergic nuclei and pathways, using micro-dissection and microchemical methods for analysis of discrete brain nuclei. Regulation and interaction with cholinergic systems will be examined using various drugs and measurement of both aminergic and cholinergic parameters. The interaction of catecholamines and various peptide hormones will also be investigated in normal states and after several different endocrine manipulations.